FlickrTags also depends on the flickr_fu gem, which in turn requires a Flickr API key. Once you've obtained your API key, put it in config/flickr.yml as follows:

key: abc123abc123abc123abc123abc123abc123abc123
secret: abc123abc123

Some of the tags require a user attribute, in which you must specify your Flickr user ID, not your Flickr screen name. If you don't know your Flickr user ID, you can look it up at http://idgettr.com/.

Because Flickr lookups are very slow, the results are cached for some time so changes on Flickr take a while to show up. By default this is about 1 hour. You can change this by setting FlickrTagsExtension.cache_timeout in your environment.rb like so:

config.after_initialize do
FlickrTagsExtension.cache_timeout = 2.days
end

Note that for this to work the value should be larger than Radiant's cache timeout (SiteController.cache_timeout) which is 5 minutes by default.

flickr:slideshow

The flickr:slideshow tag embeds a slideshow into a page (using an iframe). Photographs for the slideshow can be selected using a Flickr photoset ID or a comma-separated list of Flickr tags. For example, the tag

<r:flickr:slideshow user="10622160@N00" tags="portfolio"/>

adds a slideshow of all photographs that the Flickr user with ID 10622160@N00 has tagged as portfolio. This creates an iframe like this in the page: